CN113508940A

CN113508940A - Mask with micro-nano gradient structure

Info

Publication number: CN113508940A
Application number: CN202010280295.8A
Authority: CN
Inventors: 路芳; 司晓勤; 吴鹏飞; 卢锐
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2021-10-19

Abstract

The application discloses a mask with a micro-nano gradient structure, which comprises a surface layer and an inner layer; the skin layer comprises a spunbond nonwoven; the inner layer comprises a micro-nanofiber composite material; the micro-nanofiber composite material comprises a nano cellulose membrane and a polypropylene melt-blown non-woven fabric substrate; the nano cellulose membrane covers the surface of the polypropylene melt-blown non-woven fabric substrate; the micro-nano fiber composite material has a micro-nano gradient structure. The utility model provides a physical interception effect of gauze mask is more stable, reliable, and can have good air permeability concurrently. Can provide important guarantee for the prevention and control of infectious virus epidemic situation, has important function in the prevention and control of the epidemic situation of SARS, novel coronavirus and the like, and also has important function in the effective protection of medical care personnel and susceptible people in flu season.

Description

Mask with micro-nano gradient structure

Technical Field

The application belongs to the field of masks, and particularly relates to a mask taking a nanofiber composite material as a filter layer.

Background

In recent years, China is even affected by infectious viruses many times all over the world. According to the central control of disease in the united states, there are at least 2200 million people infected with influenza in the united states from 1/10/2019 to 1/2020/2/1, 21 of which require hospitalization and 1.2 of which die. Therefore, a high degree of infectious viruses is the biggest threat to human survival and development. The virus can be rapidly spread among organisms through tiny particles containing pathogens such as droplets, and the size of the particles is only about 100nm, so that wearing a high-filtering mask is an effective way to block the virus from spreading.

Currently, the mask achieves isolation of bacteria, PM2.5 particles, etc. mainly through two ways: (1) electrostatic adsorption belongs to an active isolation method, namely, the adsorption effect of electrostatic force between fibers in the middle layer of a mask on bacteria and tiny particles is utilized to realize isolation and protection; (2) physical isolation belongs to a passive isolation method, namely, a small pore structure of a mask is utilized to prevent bacteria and viruses from invading. The filtering layer of the medical surgical mask adopts micron-sized polypropylene fibers, has larger pore diameter, cannot effectively realize physical isolation of small-particle bacteria and viruses, and mainly adopts an electrostatic adsorption method. However, as the wearing time increases (for example, 1 to 2 hours), the breathing of the wearer makes the mask damp, the electrostatic adsorption capacity of the mask weakens, and the isolation effect gradually deteriorates. And further in view of the size of the virus, the medical surgical mask cannot realize long-term effective isolation protection. In addition, the N95-grade mask enhances the virus isolation effect by increasing the thickness of the melt-blown cloth layer, but brings larger breathing resistance and can generate adverse effects on human alveoli after being worn for a long time. Therefore, there is a need to develop a novel mask with more stable and reliable physical interception effect and excellent air permeability.

Disclosure of Invention

According to an aspect of the application, provide a gauze mask with micro-nano gradient structure, the main filter layer of this gauze mask is the nanofiber composite who has micro-nano structure, and this nanofiber composite is effectively combined by nanometer cellulose and polypropylene melt-blown non-woven fabrics and forms. The physical interception effect of the mask is more stable and reliable, and the mask can have excellent air permeability.

A mask with a micro-nano gradient structure comprises a surface layer and an inner layer;

the skin layer comprises a spunbond nonwoven;

the inner layer comprises a micro-nanofiber composite material;

the micro-nano fiber composite material comprises a nano cellulose membrane and a polypropylene melt-blown non-woven fabric substrate;

the nano cellulose membrane covers the surface of the polypropylene melt-blown non-woven fabric substrate;

the micro-nano fiber composite material has a micro-nano gradient structure.

The micro-nano gradient structure is a micro-nano structure formed by materials with micro-and nano-pore structures.

Optionally, the mask with the micro-nano gradient structure is composed of a spunbonded nonwoven fabric on the surface layer and a micro-nano fiber composite material arranged in the surface layer.

The micro-nanofiber composite material is a main filtering layer and is formed by effectively combining nano-cellulose and polypropylene melt-blown non-woven fabrics.

Specifically, a micro-nano structure fiber layer formed by the micro-nano fiber composite material is arranged between two spun-bonded non-woven fabric layers to form a sandwich structure.

The thickness of the nanometer cellulose layer and the polypropylene melt-blown micron fiber non-woven fabric layer in the micro-nano structure composite material can be adjusted.

Optionally, the breathing resistance of the mask with the micro-nano gradient structure is 5-90 Pa, and the breathing resistance is 1-80 Pa.

Optionally, the breathing resistance of the mask with the micro-nano gradient structure is lower than 90Pa, and the breathing resistance is lower than 80 Pa.

Optionally, the upper limit of the inhalation resistance of the mask with the micro-nano gradient structure is selected from 90Pa, 80Pa, 70Pa, 60Pa, 50Pa, 40Pa, 30Pa, 24Pa, 23Pa, 15Pa, 14Pa or 10 Pa; the lower limit is selected from 80Pa, 70Pa, 60Pa, 50Pa, 40Pa, 30Pa, 24Pa, 23Pa, 15Pa, 14Pa, 10Pa, or 5 Pa.

Optionally, the upper limit of the exhalation resistance of the mask with the micro-nano gradient structure is selected from 80Pa, 70Pa, 60Pa, 50Pa, 40Pa, 30Pa, 20Pa, 19Pa, 15Pa or 10 Pa; the lower limit is selected from 70Pa, 60Pa, 50Pa, 40Pa, 30Pa, 20Pa, 19Pa, 15Pa, 10Pa or 9 Pa.

Optionally, the filtering efficiency of the mask with the micro-nano gradient structure on particles with the size of 0.25-0.35 μm is more than or equal to 95%.

Optionally, the filtering efficiency of the mask with the micro-nano gradient structure on micro particles in the air is more than 95%.

Optionally, the diameter of the nanocellulose in the nanocellulose membrane layer is 5-900 nm, and the pore diameter of the nanocellulose membrane layer is 5-800 nm.

Optionally, the diameter of the micro-fiber in the polypropylene melt-blown non-woven fabric base material is 1-100 μm, and the pore size of the micro-fiber layer in the polypropylene melt-blown non-woven fabric base material is 1-300 μm.

Optionally, the diameter of the nanocellulose in the nanocellulose membrane layer is 5-600 nm, and the pore diameter of the nanocellulose membrane layer is 5-500 nm.

Optionally, the diameter of the micro-fiber in the polypropylene melt-blown non-woven fabric base material is 1-50 μm, and the pore size of the micro-fiber layer in the polypropylene melt-blown non-woven fabric base material is 1-200 μm.

Optionally, the thickness ratio of the nano cellulose membrane to the polypropylene melt-blown nonwoven fabric substrate is 1: 0.05 to 50.

Optionally, the thickness ratio of the nano cellulose film to the non-woven fabric substrate is 1: 0.3 to 13.

Optionally, the thickness ratio of the nano cellulose film to the non-woven fabric substrate may be 1: 0.3, 1: 0.5, 1: 0.6, 1: 1. 1: 2. 1: 3. 1: 4. 1: 5. 1: 6. 1: 7. 1: 8. 1: 9. 1: 13.

optionally, the thickness of the nanofiber membrane and the microfiber membrane in the micro-nanofiber composite material can be adjusted.

The micro-nano fiber composite material used by the mask with the micro-nano gradient structure effectively combines micron materials such as nano-cellulose and polypropylene together to construct the composite material with the micro-nano gradient structure, has the advantages of small filtration resistance and good filtration performance, and can realize high-efficiency graded filtration of particles with different sizes.

Optionally, the preparation method of the micro-nanofiber composite material comprises one of an electrostatic spinning method and a spray coating method.

Optionally, the electrospinning method comprises at least:

and (3) performing electrostatic spinning on the electrostatic spinning solution containing the nano-cellulose and the polymer on a non-woven fabric substrate to obtain the micro-nano fiber composite material.

Optionally, in the electrostatic spinning solution, the mass concentration of the nanocellulose is 0.5-25%.

Optionally, the mass concentration of the nanocellulose is 0.5-5%.

Optionally, the method for preparing the electrostatic spinning solution containing the nanocellulose and the polymer at least comprises the following steps:

and mixing the nano-cellulose aqueous solution and the solution containing the polymer to obtain the electrostatic spinning solution containing the nano-cellulose and the polymer.

Optionally, the means of mixing comprises stirring.

Optionally, the stirring time is 0.1-24 h.

Optionally, in the nanocellulose aqueous solution, the mass concentration of the nanocellulose is 0.5-50%.

Optionally, in the nanocellulose aqueous solution, the mass concentration of the nanocellulose is 0.5-25%.

Optionally, in the aqueous solution of nanocellulose, the upper limit of the mass concentration of nanocellulose is selected from 8%, 10%, 12%, 14%, 16%, 18%, 20% or 25%; the lower limit is selected from 0.5%, 1%, 2%, 5%, 10%, 16%, 18%, 20% or 25%.

Optionally, the diameter of the nanocellulose in the nanocellulose aqueous solution is 5-900 nm.

Optionally, the length of the nanocellulose in the nanocellulose aqueous solution is 0.01-1000 μm.

Optionally, the diameter of the nanocellulose in the nanocellulose aqueous solution is 10-600 nm.

Optionally, the length of the nano-cellulose in the nano-cellulose aqueous solution is 0.1-790 mu m.

Optionally, the mass concentration of the polymer in the solution containing the polymer is 0.5-50%.

Optionally, the mass concentration of the polymer is 5-15%.

Alternatively, the method for preparing the solution containing the polymer at least comprises: the mixture containing the polymer and the solvent I is mixed.

Optionally, the means of mixing includes stirring and ultrasonic dispersion.

Optionally, the stirring time is 0.5-36 h, and the ultrasonic dispersion time is 0.1-5 h.

Optionally, the ratio of the mass of the polymer to the volume of solvent I is 1 g: 2-200 mL.

Optionally, the ratio of the mass of the polymer to the volume of solvent I is 1 g: 9-11 mL.

Optionally, the polymer comprises at least one of polyvinylpyrrolidone, polyvinyl butyral, polycaprolactone, poly (l-lactide-co-glycolic acid), poly (l-lactide acid), polyacrylonitrile, polyvinylidene fluoride, cellulose acetate, polyurethane.

Optionally, the solvent I comprises at least one of ethanol, acetone, N-dimethylformamide, N-dimethylacetamide.

Optionally, the process conditions of the electrostatic spinning are as follows: the ambient temperature of electrostatic spinning is 2-90 ℃; the voltage of electrostatic spinning is 0.5-80 kv; the distance between the needle point of the electrostatic spinning device and the non-woven fabric receiving base material is 0.2-50 cm.

Optionally, the ambient temperature of the electrostatic spinning is 5-60 ℃, the voltage of the electrostatic spinning is 0.5-50 kv, and the distance between the needle point of the electrostatic spinning device and the receiving non-woven fabric substrate is 0.2-10 cm.

Optionally, the ambient temperature of the electrostatic spinning is 5-35 ℃, the voltage of the electrostatic spinning is 1-20 kv, and the distance between the needle point of the electrostatic spinning device and the receiving non-woven fabric substrate is 0.5-3 cm.

Specifically, the electrospinning method at least comprises:

(1) adding the polymer into a solvent I system, stirring and ultrasonically dispersing to obtain a uniform and transparent solution I;

(2) adding the nano-cellulose aqueous solution into the solution, and stirring to obtain a uniformly dispersed solution II, namely the electrostatic spinning solution;

(3) and (3) placing the electrostatic spinning solution into an injector, connecting the injector with a jet needle, performing electrostatic spinning on the non-woven fabric substrate through an electrostatic spinning device, drying to obtain a nano cellulose membrane, and further combining with the non-woven fabric to form the fiber composite material with the micro-nano gradient structure.

Optionally, the spraying process comprises at least:

and spraying a solution containing nano-cellulose on a non-woven fabric substrate to obtain the micro-nano fiber composite material.

Optionally, in the solution containing the nanocellulose, the mass concentration of the nanocellulose is 0.1-50%.

Optionally, in the solution containing the nanocellulose, the mass concentration of the nanocellulose is 0.1-25%.

Optionally, the method for preparing the solution containing the nanocellulose at least comprises the following steps: the mixture containing the nano-cellulose and the solvent II is mixed.

Optionally, the means of mixing includes stirring and ultrasonic dispersion.

Optionally, the stirring time is 0.5-36 h, and the ultrasonic dispersion time is 0.1-16 h.

Optionally, the ratio of the mass of the nanocellulose to the volume of solvent II is 1 g: 2-1000 mL.

Optionally, the ratio of the mass of the nanocellulose to the volume of solvent II is 1 g: 50-167 mL.

Optionally, the solvent II comprises at least one of water, methanol, ethanol, propanol, diethyl ether, acetone, and 1, 4-dioxane.

Optionally, the diameter of the nano-cellulose is 5-900 nm.

Optionally, the length of the nano-cellulose is 0.01-1000 μm.

Optionally, the diameter of the nano-cellulose is 5-300 nm.

Optionally, the length of the nano-cellulose is 0.1-500 μm.

Optionally, the spraying speed of the solution is 0.1-50 ml/min.

Optionally, the spraying speed of the solution is 0.5-4 ml/min.

Specifically, the spraying method at least comprises:

adding the nano-cellulose into the solvent II, stirring and ultrasonically dispersing uniformly to obtain a solution III, uniformly spraying the solution III on a non-woven fabric at high pressure, and drying to obtain the fiber composite material with the micro-nano gradient structure.

The beneficial effects that this application can produce include:

1) the utility model provides a gauze mask with micro-nano gradient structure, on the basis of current polypropylene melt-blown non-woven fabrics, regard as the main filter layer of novel anti-virus gauze mask with the fibre combined material who has micro-nano structure, the plant fiber who will contain nano structure combines the new material of preparing on current micron order polypropylene melt-blown cloth fibre, good gas permeability and higher filtration efficiency have, can realize the high-efficient hierarchical filtration to different size granule, its physics interception effect is more stable, reliable, and can have good air permeability concurrently, the problem of polypropylene melt-blown non-woven fabrics filter layer in aspects such as the separation to the virus and air permeability has been solved.

2) The mask with the micro-nano gradient structure is simple in production process, easy to operate and easy to realize large-scale production.

3) The gauze mask that has micro-nano gradient structure that this application provided can provide important guarantee for the prevention and control of infectious virus epidemic situation, has important effect in epidemic situation prevention and control such as SARS and novel coronavirus, also can play important effect in the effective protection of flu season medical personnel and susceptible crowd.

Drawings

Fig. 1 is a scanning electron microscope SEM image of the micro-nanofiber composite material of example 1; wherein, figure 1) a is a non-woven fabric base material layer; fig. 1) b is a nanofiber layer.

Fig. 2 is a scanning electron microscope SEM image of the micro-nanofiber composite of example 10; wherein fig. 2) a is a non-woven fabric substrate layer; fig. 2) b is a nanofiber layer.

Fig. 3 is a schematic view of the micro-nanofiber composite and the spunbond nonwoven fabric layer combined together.

Fig. 4 is a photograph of the mask with the micro-nano gradient structure of the present application.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were purchased commercially, unless otherwise specified.

Model number of the electrospinning device, HZ-GTX-01, was collected by the manufacturer for electrospinning.

Scanning Electron Microscope (SEM) analysis was performed using a JEOL JSM-7800F instrument under analysis conditions Vacc of 1kv and WD of 8.0 mm.

In the embodiment, the inhalation resistance and the exhalation resistance of the mask are tested by adopting a mask exhalation resistance tester. The model SC-FT-1406 of the mask breathing resistance tester is that the flow is 85L/min.

In the embodiment, the filtering efficiency of the mask to tiny particles in the air is tested by adopting a mask filtering efficiency tester. Wherein the particle diameter of the tiny particles in the air is between 0.25 and 0.35 μm, the model of the mask filtration efficiency tester is SC-FT-1406, and the test condition is 85L/min.

Fig. 3 is a schematic diagram of the micro-nano fiber composite material and the spunbonded non-woven fabric layer combined together, and a micro-nano structure fiber layer formed by the micro-nano fiber composite material is arranged between the two spunbonded non-woven fabric layers to form a sandwich structure.

Fig. 4 is a photograph of the mask with the micro-nano gradient structure of the present application, which is similar to the appearance of the existing mask, but has the advantages of small breathing resistance, good filtering performance, etc.

Example 1

Adding 2.0g of polyvinylpyrrolidone into 18ml of ethanol solvent system, stirring for 1h, performing ultrasonic dispersion for 0.2h to obtain a uniform and transparent solution, adding 2.0g of nano-cellulose aqueous solution with the mass concentration of 10% into the solution, wherein the diameter of the nano-cellulose is 50-600 nm and the length of the nano-cellulose is 0.1-790 mu m, stirring for 2h to obtain a uniformly dispersed electrostatic spinning solution, the mass concentration of the nano-cellulose in the electrostatic spinning solution is 1.1%, placing the electrostatic spinning solution into an injector, connecting the injector with a jet needle, performing electrostatic spinning on a polypropylene non-woven fabric substrate at 15 ℃ through an electrostatic spinning device, the voltage of the electrostatic spinning is 1kv, the distance between the needle point of the electrostatic spinning device and a receiving device is 1cm, and drying to obtain a nano-cellulose membrane, and the thickness ratio of the nano cellulose membrane obtained by electrostatic spinning to the non-woven fabric substrate is 1: and 5, obtaining the micro-nano fiber composite material formed by combining the polypropylene non-woven fabric. Is recorded as sample # 1. FIG. 1 is a SEM image of sample No. 1; wherein, figure 1) a is a non-woven fabric base material layer; fig. 1) b is a nanofiber layer. As can be seen from the SEM image, the diameter of the nanocellulose is 100-900 nm, the pore diameter of the nanocellulose membrane is 100-800 nm, the diameter of the non-woven fabric substrate is 1-50 μm, and the pore diameter of the non-woven fabric substrate is 1-200 μm.

Example 2

Adding 5.8g of L-polylactic acid into 50ml of acetone solvent system, stirring for 3h, performing ultrasonic dispersion for 1h to obtain a uniform and transparent solution, adding 7.2g of nano-cellulose aqueous solution with the mass concentration of 10% into the solution, wherein the diameter of the nano-cellulose is 5-200 nm, the length of the nano-cellulose is 0.1-500 mu m, stirring for 2h to obtain uniformly dispersed electrostatic spinning solution, and the mass concentration of the nano-cellulose in the electrostatic spinning solution is 1.4%. And then placing the electrostatic spinning solution into an injector, connecting the injector with a jet needle, performing electrostatic spinning on a polypropylene non-woven fabric substrate through an electrostatic spinning device at 10 ℃, wherein the voltage of the electrostatic spinning is 5kv, the distance between the needle point of the electrostatic spinning device and a receiving device is 1.5cm, drying to obtain a nano cellulose membrane, and the thickness ratio of the nano cellulose membrane to the non-woven fabric substrate obtained by the electrostatic spinning is 3: and 2, wherein the diameter of the nano-cellulose is 100-600 nm, the aperture of the nano-cellulose membrane is 20-300 nm, the diameter of the non-woven fabric base material is 10-100 mu m, and the aperture of the non-woven fabric base material is 50-200 mu m, so that the micro-nano fiber composite material formed by combining the nano-cellulose with the polypropylene non-woven fabric is obtained. Is recorded as sample # 2.

Example 3

Adding 2.0g of nano-cellulose into 100ml of water, wherein the mass concentration of the nano-cellulose is 2.0%, the diameter of the nano-cellulose is 5-100 nm, the length of the nano-cellulose is 0.1-200 mu m, after stirring for 5 hours, performing ultrasonic dispersion for 1 hour to obtain a uniformly dispersed nano-cellulose solution, then uniformly spraying the solution on a polypropylene non-woven fabric through a high-pressure spray gun at the speed of 0.5ml/min, drying to obtain a micro-nano fiber composite material with a micro-nano gradient structure, and the thickness ratio of the nano-cellulose membrane to the non-woven fabric substrate is 1: 5. record as sample # 3. FIG. 2 is a SEM image of sample No. 3; wherein fig. 2) a is a non-woven fabric substrate layer; fig. 2) b is a nanofiber layer. As can be seen from the SEM image, the diameter of the nanocellulose is 5-100 nm, the pore diameter of the nanocellulose membrane is 10-290 nm, the diameter of the non-woven fabric substrate is 2-50 μm, and the pore diameter of the non-woven fabric substrate is 5-200 μm.

Example 4

Adding 20g of nano-cellulose into 1500ml of acetone, wherein the mass concentration of the nano-cellulose is 1.3%, the diameter of the nano-cellulose is 10-300 nm, the length of the nano-cellulose is 0.5-400 microns, stirring the mixture for 20 hours, performing ultrasonic dispersion for 6 hours to obtain a uniformly dispersed nano-cellulose solution, then uniformly spraying the solution on a polypropylene non-woven fabric through a high-pressure spray gun at a speed of 3ml/min, drying the polypropylene non-woven fabric to obtain a micro-nano fiber composite material with a micro-nano gradient structure, and the thickness ratio of a nano-cellulose membrane to a non-woven fabric substrate is 1: 13, wherein the diameter of the nano-cellulose is 5-100 nm, the pore diameter of the nano-cellulose membrane is 10-190 nm, the diameter of the non-woven fabric base material is 1-80 μm, and the pore diameter of the non-woven fabric base material is 5-150 μm. Is recorded as sample # 4.

The experimental procedure of example 5 was the same as that of example 3, and it was required to change the water solvent to a mixed solvent of water and methanol in a volume ratio of 2: 1.

the experimental procedure of example 6 was the same as that of example 3, and it was required to change the water solvent to a mixed solvent of water and methanol in a volume ratio of 1: 1.

the experimental procedure of example 7 is the same as that of example 3, and the water solvent is changed to a mixed solvent of water and ethanol, wherein the volume ratio of the water to the ethanol is 2: 1.

the experimental procedure of example 8 is the same as that of example 3, and the water solvent is changed to a mixed solvent of water and ethanol, wherein the volume ratio of the water to the ethanol is 1: 1.

the experimental procedure of example 9 was the same as that of example 3, and it was required to change the water solvent to a mixed solvent of water and propanol in a volume ratio of 2: 1.

the experimental procedure of example 10 was the same as in example 3, and it was required to change the water solvent to a mixed solvent of water and propanol, wherein the volume ratio of water to propanol was 1: 1.

the experimental procedure of example 11 was the same as that of example 3, and it was required to change the water solvent to a mixed solvent of water and diethyl ether at a volume ratio of 2: 1.

the experimental procedure of example 12 was the same as that of example 3, and it was required to change the water solvent to a mixed solvent of water and diethyl ether in a volume ratio of 1: 1.

the experimental procedure of example 13 was the same as that of example 3, and it was required to change the water solvent to a mixed solvent of water and acetone in a volume ratio of 2: 1.

the experimental procedure of example 14 is the same as that of example 3, and the water solvent is changed to a mixed solvent of water and acetone, wherein the volume ratio of the water to the acetone is 1: 1.

the experimental procedure of example 15 is the same as that of example 4, and the water solvent is changed to a mixed solvent of water and acetone, wherein the volume ratio of the water to the acetone is 1: 2.

the experimental procedure of example 16 was the same as that of example 3, and it was necessary to change the water solvent to a mixed solvent of water and 1, 4-dioxane, wherein the volume ratio of water to 1, 4-dioxane was 2: 1.

the experimental procedure of example 17 was the same as that of example 3, and it was necessary to change the water solvent to a mixed solvent of water and 1, 4-dioxane, wherein the volume ratio of water to 1, 4-dioxane was 1: 1.

the experimental procedure of example 18 is the same as that of example 4, and it is required to change the methanol solvent to a mixed solvent of methanol and acetone in a volume ratio of 1: 2.

the experimental procedure of example 19 is the same as that of example 4, and it is required to change the ethanol solvent to a mixed solvent of ethanol and acetone in a volume ratio of 1: 2.

the experimental procedure of example 20 was the same as that of example 4, and it was required to change the propanol solvent to a mixed solvent of propanol and acetone in a volume ratio of 1: 2.

the experimental procedure of example 21 was the same as that of example 4, and it was necessary to change the ether solvent to a mixed solvent of ether and acetone in a volume ratio of 1: 2.

the experimental procedure of example 22 was the same as in example 4, and it was necessary to change the acetone solvent to a mixed solvent of acetone and 1, 4-dioxane, wherein the volume ratio of acetone to 1, 4-dioxane was 2: 1.

the experimental procedure of example 23 was the same as in example 4, and it was necessary to change the acetone solvent to a mixed solvent of acetone and 1, 4-dioxane, wherein the volume ratio of acetone to 1, 4-dioxane was 1: 1.

example 24

Sample # 1, namely a micro-nano structure fiber filter layer prepared in example 1 was used as a main internal filter layer of the novel anti-virus mask, wherein the thickness ratio of the nano cellulose layer to the polypropylene melt-blown non-woven fabric layer was 1: 5, combining the outer layer of spun-bonded non-woven fabric layer to prepare the mask with the micro-nano structure, wherein the air suction resistance is 15Pa, the air expiration resistance is 10Pa, the filtering efficiency of the mask on particles with the size of 0.25-0.35 mu m reaches 97%, and tiny particles containing pathogens, such as droplets in the air, can be effectively prevented from being sucked into a human body.

Example 25

Sample # 2 prepared in example 2, i.e., a micro-nano structure fiber filter layer, was used as a main internal filter layer of the novel anti-virus mask, wherein the thickness ratio of the nano cellulose layer to the polypropylene melt-blown non-woven fabric layer was 3: 2, combining the outer layer of spun-bonded non-woven fabric layer to prepare the mask with the micro-nano structure, wherein the air suction resistance is 24Pa, the air expiration resistance is 19Pa, the filtering efficiency of the mask on particles with the size of 0.25-0.35 mu m reaches 98%, and tiny particles containing pathogens, such as droplets in the air, can be effectively prevented from being sucked into a human body.

Example 26

Sample # 3 prepared in example 3, i.e., a micro-nano structure fiber filter layer, was used as a main internal filter layer of the novel anti-virus mask, wherein the thickness ratio of the nano cellulose layer to the polypropylene melt-blown non-woven fabric layer was 1: 5, combining the outer layer of spun-bonded non-woven fabric layer to prepare the mask with the micro-nano structure, wherein the air suction resistance is 14Pa, the air expiration resistance is 9Pa, the filtering efficiency of the mask on particles with the size of 0.25-0.35 mu m reaches 96%, and tiny particles containing pathogens, such as droplets in the air, can be effectively prevented from being sucked into a human body.

Example 27

Sample No. 4, namely a micro-nano structure fiber filter layer prepared in the example 4 is used as a main internal filter layer of the novel disease-resistant mask, wherein the thickness ratio of the nano cellulose layer to the polypropylene melt-blown non-woven fabric layer is 1: and 13, combining the outer layer of spun-bonded non-woven fabric layer to prepare the mask with the micro-nano structure, wherein the air suction resistance is 23Pa, the exhalation resistance is 20Pa, the filtering efficiency of the mask on particles with the size of 0.25-0.35 mu m reaches 99%, and tiny particles containing pathogens, such as droplets in the air, can be effectively prevented from being sucked into a human body.

Example 28

The mask is prepared by taking a polypropylene melt-blown non-woven fabric filter layer with the diameter of 1-20 mu m and the pore diameter of 5-100 mu m as a main inner filter layer of the mask and combining an outer spun-bonded non-woven fabric layer, wherein the inhalation resistance of the mask is 185Pa, the exhalation resistance of the mask is 167Pa, and the filtering efficiency of the mask on tiny particles containing pathogens such as spray in the air is 95 percent.

The experimental procedure of the embodiment 29 is the same as that of the embodiment 24, the micro-nano structure fiber filter layer needs to be changed to the sample # 5 in the embodiment 5, the inhalation resistance of the production mask is 21Pa, the exhalation resistance is 15Pa, and the filtration efficiency of the production mask on particles with the size of 0.25-0.35 μm reaches 98%.

The experimental procedure of the embodiment 30 is the same as that of the embodiment 24, the micro-nano structure fiber filter layer needs to be changed into the sample 6# in the embodiment 6, the inhalation resistance of the production mask is 14Pa, the exhalation resistance is 10Pa, and the filtration efficiency of the production mask on particles with the size of 0.25-0.35 μm reaches 97%.

The experimental procedure of the embodiment 31 is the same as that of the embodiment 24, the micro-nano structure fiber filter layer needs to be changed into the sample 7# in the embodiment 7, the inhalation resistance of the production mask is 26Pa, the exhalation resistance is 20Pa, and the filtration efficiency of the production mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of the embodiment 32 is the same as that of the embodiment 24, the micro-nano structure fiber filter layer needs to be changed into the sample # 8 in the embodiment 8, the inhalation resistance of the production mask is 16Pa, the exhalation resistance is 11Pa, and the filtration efficiency of the production mask on particles with the size of 0.25-0.35 μm reaches 97%.

The experimental procedure of the embodiment 33 is the same as that of the embodiment 24, the micro-nano structure fiber filter layer needs to be changed to the sample # 9 in the embodiment 9, the inhalation resistance of the mask is 31Pa, the exhalation resistance is 26Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of example 34 is the same as that of example 25, the micro-nano structure fiber filter layer needs to be changed to sample # 10 of example 10, the inhalation resistance of the mask is 35Pa, the exhalation resistance is 28Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of the embodiment 35 is the same as that of the embodiment 25, the micro-nano structure fiber filter layer is required to be changed into the sample # 11 in the embodiment 11, the inhalation resistance of the produced mask is 34Pa, the exhalation resistance is 30Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of the embodiment 36 is the same as that of the embodiment 25, the micro-nano structure fiber filter layer is changed to the sample # 12 in the embodiment 12, the inhalation resistance of the produced mask is 24Pa, the exhalation resistance is 19Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 98%.

The experimental procedure of example 37 is the same as that of example 25, the micro-nano structure fiber filter layer needs to be changed to sample # 13 in example 13, the inhalation resistance of the mask is 20Pa, the exhalation resistance is 16Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 97%.

The experimental procedure of example 38 is the same as that of example 25, the micro-nano structure fiber filter layer needs to be changed to sample # 14 in example 14, the inhalation resistance of the mask is 15Pa, the exhalation resistance is 10Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 95%.

The experimental procedure of the embodiment 39 is the same as that of the embodiment 26, the micro-nano structure fiber filter layer is required to be changed into the sample No. 15 in the embodiment 15, the inhalation resistance of the produced mask is 40Pa, the exhalation resistance is 35Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of the embodiment 40 is the same as that of the embodiment 26, the micro-nano structure fiber filter layer needs to be changed into the sample # 16 in the embodiment 16, the inhalation resistance of the production mask is 39Pa, the exhalation resistance is 32Pa, and the filtration efficiency of the production mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of the embodiment 41 is the same as that of the embodiment 26, the micro-nano structure fiber filter layer is required to be changed into the sample # 17 in the embodiment 17, the inhalation resistance of the produced mask is 35Pa, the exhalation resistance is 29Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of example 42 is the same as that of example 26, the micro-nano structure fiber filter layer needs to be changed to sample # 18 in example 18, the inhalation resistance of the mask is 18Pa, the exhalation resistance is 14Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 96%.

The experimental procedure of example 43 is the same as that of example 26, the micro-nano structure fiber filter layer needs to be changed to sample # 19 in example 19, the inhalation resistance of the mask is 22Pa, the exhalation resistance is 19Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 97%.

The experimental procedure of the example 44 is the same as that of the example 27, the micro-nano structure fiber filter layer needs to be changed to the sample # 20 in the example 20, the inhalation resistance of the production mask is 31Pa, the exhalation resistance is 27Pa, and the filtration efficiency of the production mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of example 45 is the same as that of example 27, the micro-nano structure fiber filter layer needs to be changed to sample # 21 in example 21, the inhalation resistance of the mask is 38Pa, the exhalation resistance is 34Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

The experimental procedure of example 46 is the same as that of example 27, the micro-nano structure fiber filter layer needs to be changed to sample # 22 in example 22, the inhalation resistance of the mask is 23Pa, the exhalation resistance is 18Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 97%.

The experimental procedure of the embodiment 47 is the same as that of the embodiment 27, the micro-nano structure fiber filter layer is changed to the sample # 23 in the embodiment 23, the inhalation resistance of the produced mask is 26Pa, the exhalation resistance is 21Pa, and the filtration efficiency of the mask on particles with the size of 0.25-0.35 μm reaches 99%.

Although the present invention has been described with reference to a few preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A mask with a micro-nano gradient structure is characterized by comprising a surface layer and an inner layer;

the skin layer comprises a spunbond nonwoven;

the inner layer comprises a micro-nanofiber composite material;

the micro-nanofiber composite material comprises a nano cellulose membrane and a polypropylene melt-blown non-woven fabric substrate;

the micro-nano fiber composite material has a micro-nano gradient structure.

2. The mask with the micro-nano gradient structure according to claim 1, wherein the inhalation resistance of the mask is 5-90 Pa, and the exhalation resistance of the mask is 1-80 Pa;

preferably, the filtering efficiency of the mask to particles with the size of 0.25-0.35 μm is more than or equal to 95%.

3. The mask with the micro-nano gradient structure according to claim 1, wherein the diameter of the nanocellulose in the nanocellulose membrane layer is 5-900 nm, and the pore diameter of the nanocellulose membrane layer is 5-800 nm;

the diameter of the micron fiber in the polypropylene melt-blown non-woven fabric base material is 1-100 mu m, and the pore size of the micron fiber layer in the polypropylene melt-blown non-woven fabric base material is 1-300 mu m;

preferably, the diameter of the nano cellulose in the nano cellulose membrane layer is 5-600 nm, and the pore diameter of the nano cellulose membrane layer is 5-500 nm;

the diameter of the micron fiber in the polypropylene melt-blown non-woven fabric base material is 1-50 mu m, and the pore diameter of the micron fiber layer in the polypropylene melt-blown non-woven fabric base material is 1-200 mu m.

4. The mask with the micro-nano gradient structure according to claim 1, wherein the thickness ratio of the nano cellulose membrane to the polypropylene melt-blown non-woven fabric substrate is 1: 0.05 to 50;

preferably, the thickness ratio of the nano cellulose membrane to the polypropylene melt-blown non-woven fabric substrate is 1: 0.3 to 13.

5. The mask with the micro-nano gradient structure of claim 1, wherein the preparation method of the micro-nano fiber composite material comprises one of an electrospinning method and a spraying method.

6. The mask with the micro-nano gradient structure according to claim 5, wherein the electrospinning method at least comprises:

performing electrostatic spinning on an electrostatic spinning solution containing nano-cellulose and a polymer on a non-woven fabric substrate to obtain the micro-nanofiber composite material;

preferably, in the electrostatic spinning solution, the mass concentration of the nano-cellulose is 0.5-25%;

preferably, the mass concentration of the nano-cellulose is 0.5-5%.

7. The mask with the micro-nano gradient structure according to claim 6, wherein the preparation method of the electrospinning solution containing nanocellulose and polymer at least comprises:

mixing a nano-cellulose aqueous solution and a solution containing a polymer to obtain the electrostatic spinning solution containing the nano-cellulose and the polymer;

preferably, in the nano-cellulose aqueous solution, the mass concentration of nano-cellulose is 0.5-50%;

preferably, the mass concentration of the nano-cellulose is 0.5-25%;

preferably, the diameter of the nano-cellulose in the nano-cellulose aqueous solution is 5-900 nm;

preferably, the length of the nano-cellulose in the nano-cellulose aqueous solution is 0.01-1000 μm;

further preferably, the diameter of the nano-cellulose in the nano-cellulose aqueous solution is 10-600 nm;

preferably, the length of the nano-cellulose in the nano-cellulose aqueous solution is 0.1-790 mu m.

8. The mask with the micro-nano gradient structure according to claim 7, wherein the mass concentration of the polymer in the solution containing the polymer is 0.5-50%;

preferably, the mass concentration of the polymer is 5-15%;

preferably, the method for preparing the polymer-containing solution at least comprises: mixing a mixture containing a polymer and a solvent I;

the ratio of the mass of the polymer to the volume of the solvent I is 1 g: 2-200 mL;

preferably, the ratio of the mass of the polymer to the volume of the solvent I is 1 g: 9-11 mL;

preferably, the polymer comprises at least one of polyvinylpyrrolidone, polyvinyl butyral, polycaprolactone, poly (L-lactic-co-glycolic acid), poly (L-lactic acid), polyacrylonitrile, polyvinylidene fluoride, cellulose acetate, polyurethane;

preferably, the solvent I comprises at least one of ethanol, acetone, N-dimethylformamide, N-dimethylacetamide.

9. The mask with the micro-nano gradient structure according to claim 6, wherein the electrostatic spinning process conditions are as follows: the ambient temperature of electrostatic spinning is 2-90 ℃; the voltage of electrostatic spinning is 0.5-80 kv; the distance between the needle point of the electrostatic spinning device and the non-woven fabric receiving base material is 0.2-50 cm;

preferably, the ambient temperature of electrostatic spinning is 5-60 ℃, the voltage of electrostatic spinning is 0.5-50 kv, and the distance between the needle point of the electrostatic spinning device and the non-woven fabric receiving base material is 0.2-10 cm;

more preferably, the ambient temperature of the electrostatic spinning is 5-35 ℃, the voltage of the electrostatic spinning is 1-20 kv, and the distance between the needle point of the electrostatic spinning device and the receiving non-woven fabric base material is 0.5-3 cm.

10. The mask with the micro-nano gradient structure according to claim 5, wherein the spraying method at least comprises:

spraying a solution containing nano-cellulose on a non-woven fabric substrate to obtain the micro-nanofiber composite material;

preferably, in the solution containing the nano-cellulose, the mass concentration of the nano-cellulose is 0.1-50%;

preferably, the mass concentration of the nano-cellulose is 0.5-5%;

preferably, the method for preparing the solution containing nanocellulose at least comprises: mixing a mixture containing nano-cellulose and a solvent II;

the volume ratio of the mass of the nano-cellulose to the solvent II is 1 g: 2-1000 mL;

preferably, the ratio of the mass of the nanocellulose to the volume of the solvent II is 1 g: 50-167 mL;

preferably, the solvent II comprises at least one of water, methanol, ethanol, propanol, diethyl ether, acetone and 1, 4-dioxane;

preferably, the diameter of the nano-cellulose is 5-900 nm;

preferably, the length of the nano-cellulose is 0.01-1000 μm;

preferably, the diameter of the nano-cellulose is 5-300 nm;

preferably, the length of the nano-cellulose is 0.1-500 μm;

preferably, the spraying speed of the solution is 0.1-50 ml/min;

preferably, the spraying speed of the solution is 0.5-4 ml/min.